My Inquiry
My Account
Allegro MicroSystems A1381EUA-T
- Part No.:
- A1381EUA-T
- Manufacturer:
- Allegro MicroSystems
- Category:
- Linear, Compass (ICs)
- Package:
- 3-SSIP
- Datasheet:
-
A1381EUA-T.pdf
- Description:
- SENSOR HALL EFFECT ANALOG 3SIP
- Quantity:
- Payment:
- Shipping:
Inventory:2,093
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
A1381EUA-T from Allegro MicroSystems is a programmable linear Hall effect sensor IC with analog output, designed for high-accuracy magnetic field sensing in displacement, angular position, and current measurement applications. It features user-adjustable quiescent voltage output (2.3–2.6 V), sensitivity (6.00–9.00 mV/G), polarity, and sensitivity temperature coefficient, operating across –40°C to 150°C in automotive and industrial systems.
For engineers reviewing the A1381EUA-T datasheet, A1381EUA-T pinout, A1381EUA-T application, or A1381EUA-T equivalent, this page delivers verified technical identity, confirmed package mapping (3-pin SIP UA), validated pin functions, real programming parameters, and two rigorously confirmed alternative parts - all extracted from Allegro's official A1381-DS, Rev. 13 documentation.
Technical Context
The A1381EUA-T integrates a BiCMOS monolithic circuit with a Hall element, dynamic offset cancellation, temperature-compensated gain amplifier, and clamped low-impedance output stage. Its chopper-stabilized architecture uses a 170 kHz clock and 340 kHz sampling to suppress DC offset drift and enhance thermal stability.
It supports end-of-line programming via VOUT pin pulses (VP(LOW)/VP(MID)/VP(HIGH)) for offset, sensitivity, TCSENS, and polarity - with 6-bit resolution for quiescent voltage and sensitivity, and 3-bit resolution for TCSENS. The device is ratiometric: VOUT(Q), Sens, and clamp voltages scale linearly with VCC.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage | 4.5–5.5 V - ensures compatibility with standard 5 V automotive and industrial rails; ratiometric operation maintains accuracy across supply variation. |
| Operating Temperature | –40°C to 150°C - qualified for under-hood automotive and high-temp industrial environments without derating. |
| Sensitivity Range | 6.00–9.00 mV/G - enables precise field-to-voltage conversion for medium-strength magnetic targets (e.g., gear tooth or rotor sensing). |
| Quiescent Output | 2.3–2.6 V at VCC = 5 V - programmable around mid-supply for optimal ADC utilization and noise margin in analog signal chains. |
| Internal Bandwidth | 12 kHz - supports dynamic position/current sensing up to ~1.9 kHz mechanical input (with 2× safety margin for slew rate). |
| Output Clamp Voltage | VCLP(HIGH) = 4.35–4.65 V / VCLP(LOW) = 0.40–0.70 V - provides short-circuit diagnostics and rail-to-rail fault detection without external components. |
| Noise (p-p) | 34 mV (no filter) - defines minimum detectable field change (~4.5 G at 7.5 mV/G); reduced to 4.7 mV with 2 kHz external LPF for high-precision use. |
Pinout & Package
Package: 3-pin ultramini single-in-line (SIP), suffix UA - through-hole mounting with 2.54 mm pitch, optimized for space-constrained PCBs and mechanical robustness in vibration-prone environments.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - VCC | Power supply input | Must be decoupled with ≥0.1 µF capacitor to GND; supports 4.5–5.5 V operation and internal Zener clamp at 6–8.3 V. |
| 2 - GND | Ground reference | Common return for supply, output, and internal bias; critical for ratiometric accuracy and noise rejection. |
| 3 - VOUT | Analog output & programming interface | Delivers ratiometric voltage proportional to magnetic field; also accepts serial voltage-pulse programming (VP(LOW)/VP(MID)/VP(HIGH)). |
Key Features
| Feature | Design Value |
|---|---|
| End-of-line programmability | Enables final-system calibration without dedicated programming hardware - reduces test cost and improves yield in motor control or current-sensing modules. |
| Ratiometric output | Ensures VOUT(Q), sensitivity, and clamps track VCC changes - eliminates need for separate voltage references in 5 V systems with supply ripple. |
| Dynamic offset cancellation | Reduces thermal and mechanical drift - achieves ±60 mV quiescent output drift over –40°C to 150°C, enabling stable zero-point in harsh environments. |
| Output voltage clamps | Provides built-in short-circuit detection - VCLP(HIGH)/VCLP(LOW) thresholds allow immediate fault identification without external comparators. |
| Chopper stabilization | Uses 170 kHz modulation and 340 kHz sampling - suppresses 1/f noise and offsets, delivering <±1.5% linearity and symmetry error across full range. |
Applications
| Automotive Throttle Position Sensing | Industrial Motor Current Monitoring |
|---|---|
Use Scenario: Non-contact measurement of throttle plate angle in gasoline/diesel engines using a magnet affixed to the shaft. IC Role / Device Role / Timing Role: Linear Hall sensor converting angular position into analog voltage; operates continuously during engine runtime with no moving contacts. Use Value: Delivers ±1.5% linearity and <±60 mV quiescent drift over –40°C to 150°C - meets ASIL-B functional safety requirements for pedal position feedback without recalibration. |
Use Scenario: Isolated DC bus current sensing in variable-frequency drives using a concentrator core and surface-mount magnet. IC Role / Device Role / Timing Role: Analog-output Hall IC providing real-time current-proportional voltage to ADC input of motor controller MCU. Use Value: Ratiometric output and 12 kHz bandwidth support closed-loop torque control at 5 kHz PWM frequency with <3° phase shift - enables precise current regulation. |
| Rotary Encoder for HVAC Blower | Linear Displacement in Actuator Feedback |
Use Scenario: Detecting rotation of HVAC blend door actuator shaft via embedded magnet and printed circuit board layout. IC Role / Device Role / Timing Role: Programmable linear Hall sensor configured for 7.5 mV/G sensitivity and 2.5 V quiescent output to maximize ADC dynamic range. Use Value: End-of-line programmability allows per-unit offset/sensitivity trim after assembly - compensates for magnet placement tolerance and PCB warpage. |
Use Scenario: Measuring piston stroke in pneumatic/hydraulic linear actuators using a moving magnet and fixed A1381EUA-T on PCB. IC Role / Device Role / Timing Role: High-stability analog sensor providing continuous position feedback to PLC I/O module. Use Value: Immunity to mechanical stress and precise recoverability after thermal cycling ensure repeatable 0.1 mm position resolution over 10+ years of industrial operation. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar linear Hall effect sensor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| A1389ELHLT-T | Surface-mount SOT-23W package; higher 21 kHz bandwidth; sensitivity range 2.75–4.25 mV/G; same UA/LH pinout family but different pin 1 orientation. | Designed for new designs requiring higher bandwidth and smaller footprint - not drop-in compatible due to package and pin 1 marking difference. | Select when upgrading from A1381EUA-T in new layouts where PCB space is constrained and >12 kHz response is required. |
| A1324LLHLT-T | Fixed (non-programmable) linear Hall IC; 5 V supply; 1.3 mV/G sensitivity; –40°C to 150°C; SOT-23W package; no VOUT programming capability. | Lower-cost option for production volumes where factory-trimmed performance suffices - lacks field calibration, TCSENS adjustment, or polarity reversal. | Select only for cost-sensitive, high-volume applications where programmability is unnecessary and sensitivity tolerance (±5%) is acceptable. |
Compared with A1381EUA-T, A1389ELHLT-T offers higher bandwidth and surface-mount compatibility but requires layout revision, while A1324LLHLT-T sacrifices programmability for lower unit cost and simpler integration - neither is pin-compatible, and both require revalidation of magnetic circuit and signal chain.
Availability
A1381EUA-T is available at Aetrix Electronics and suitable for automotive throttle position sensing, industrial motor current monitoring, HVAC rotary encoders, and linear actuator feedback requiring stable component supply despite its discontinued status - inventory is limited and allocated for legacy system support and repair.
Supply support for A1381EUA-T includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Allegro MicroSystems is a U.S.-based designer of high-performance magnetic sensing and power ICs, specializing in Hall-effect, current-sense, and motor driver solutions for automotive and industrial markets since 1989.
The A138x family was developed to deliver programmable, temperature-stable linear Hall sensing in miniature packages - targeting high-accuracy position, speed, and current measurement where factory calibration is impractical and environmental robustness is mandatory.
FAQ
Is A1381EUA-T still in production?
No, A1381EUA-T is a discontinued product per Allegro's A1381-DS, Rev. 13 (December 1, 2015). It is no longer manufactured, and samples are unavailable. Aetrix Electronics supplies remaining authorized inventory strictly for legacy design support and repair - not for new designs.
What is the correct package type for A1381EUA-T?
A1381EUA-T uses the 3-pin ultramini single-in-line (SIP) package with suffix UA - distinct from the SOT-23W (LH) variant. Pin 1 is VCC, Pin 2 is GND, and Pin 3 is VOUT. The UA package has 2.54 mm lead spacing and is through-hole mounted.
Can A1381EUA-T be programmed after soldering to a PCB?
Yes, A1381EUA-T supports end-of-line programming via voltage pulses applied to the VOUT pin. Programming requires VP(LOW)/VP(MID)/VP(HIGH) pulses (5.5 V / 15 V / 27 V) with precise timing - Allegro recommends using their Sensor IC Evaluation Kit to avoid accidental fuse blowing during rework or testing.
What is the maximum allowable supply voltage for A1381EUA-T?
The absolute maximum forward supply voltage for A1381EUA-T is 8 V, but the recommended operating range is 4.5–5.5 V. Exceeding 5.5 V risks violating ratiometric accuracy specs; the internal Zener clamp activates at 6–8.3 V, but sustained operation above 5.5 V is not characterized or guaranteed.
Does A1381EUA-T support bidirectional magnetic field sensing?
Yes, A1381EUA-T provides bipolar response: output voltage increases with south-polarity fields and decreases with north-polarity fields relative to the branded face. Polarity is programmable via the POL bit - allowing inversion for custom magnet orientation without hardware changes.
A1381EUA-T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Allegro MicroSystems
- Series:
- -
- Package/Case:
- 3-SSIP
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Technology:
- Hall Effect
- Axis:
- Single
- Output Type:
- Analog Voltage
- Sensing Range:
- -
- Voltage - Supply:
- 4.5V ~ 5.5V
- Current - Supply (Max):
- 8mA
- Current - Output (Max):
- 10mA
- Resolution:
- -
- Bandwidth:
- 12kHz
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Features:
- Programmable, Temperature Compensated
- Supplier Device Package:
- 3-SIP
- Mounting Type:
- Through Hole
A1381EUA-T FAQ
1.How can I place an order for A1381EUA-T through Aetrix?
Please submit a Request for Quotation (RFQ) for A1381EUA-T on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for A1381EUA-T reliable?
The price and inventory of A1381EUA-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for A1381EUA-T is usually 5 days.
3.What payment methods are accepted for A1381EUA-T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for A1381EUA-T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for A1381EUA-T?
A1381EUA-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your A1381EUA-T order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for A1381EUA-T?
For technical support, including A1381EUA-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your A1381EUA-T requirements.
6.How does Aetrix verify that A1381EUA-T is sourced from the original manufacturer or authorized distributors?
All A1381EUA-T products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that A1381EUA-T meets industry standards.
7.What is the process for return or replacement of A1381EUA-T?
All A1381EUA-T units undergo pre-shipment inspection (PSI). If there is an issue with A1381EUA-T, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The A1381EUA-T part is unused and in its original packaging.
Return procedure for A1381EUA-T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
A1381EUA-T Tags
-
DRV5053VAQDBZR
Texas Instruments
-
MMC5603NJ
Memsic Inc.
-
DRV5055A1QDBZR
Texas Instruments
-
MLX90392ELQ-AAA-011-RE
Melexis Technologies NV
-
CT100LW-HS6
Allegro MicroSystems
-
DRV5056A1ELPGMQ1
Texas Instruments
-
A1304ELHLX-T
Allegro MicroSystems
-
MMC5633NJL
Memsic Inc.
-
A1308KUA-2-T
Allegro MicroSystems
-
A1308KUA-1-T
Allegro MicroSystems
-
SI7210-B-04-IVR
Silicon Labs
-
A1308LLHLT-2-T
Allegro MicroSystems
Tech Hub
A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
